[gta02-core] GSM modem [was Re. Status & next milestone for GTA02-core?]
werner at openmoko.org
Mon Aug 3 16:29:20 CEST 2009
?lvaro Lopes wrote:
> I'll be honest here. Even at "typical" consumption the Option chip seems
> to draw up to 1.1A @ 3.6V.
I think this is maximum average (over some period of time) current.
E.g., when sending, you wouldn't draw more than 4 Ws within a 1 s
interval, some of which will be in the form of 3A spikes.
> True, but USB is less error-prone, less sensitive to EMI.
Bah, if we can't get UART right over a few cm ... ;-) One problem
with USB is that it has periodic activity, even if "idle". So you
need elaborate fallback schemes to make it really stop doing
> As long as we can get the schematic "non-intrusive", meaning it does
> not require changing the already drawn ones.
Telit should be a fairly direct replacement for the Calypso.
Option would be worse, because it means that BT and modem need
to be rotated, since we only have a single USB bus. Also, I've
never seen our BT module being used with UART.
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